The present invention relates in general to the design and construction of a fuel filter and the integration of a fuel pump with the fuel filter. More specifically the present invention relates to the enhancement of a fuel filter design by adding user-friendly features and beneficial performance features. The integration of the fuel pump is configured so as to maximize the versatility of the compatible pump and filter combinations.
Some of the benefits of integrating the fuel filter and fuel pump into a single assembly is to reduce the number of interfacing components, reduce the number of connections, and reduce the overall space requirements. When the fuel filter and fuel pump are separately packaged and assembled into the engine, each component requires its own mounting provisions and connection ports and fittings and its own interconnecting conduits. The space requirements within the vehicle engine to separately position and mount the two components are greater than when the fuel pump is directly integrated into combination with the fuel filter housing. When these two separate components are installed as separate items, more time is required in order to perform the mounting steps and the interconnecting steps for the various flow lines and conduits.
The concept of "integration" as used herein refers to the unitizing of the fuel pump into or onto the fuel filter housing. This is achieved by configuring the unitary casting used for the filter housing with suitable mounting provisions for the fuel pump. In addition to the inclusion of mounting provisions for the fuel pump as part of the filter housing, the fluid connection between the pump and the filter housing is direct (i.e., contiguous). As a result of this direct connection, there is no need to provide or use any additional fluid conduits in order to separately connect the fuel outlet of the fuel pump to the fuel inlet of the filter housing. As indicated, this direct connection eliminates the need for separate interfacing conduits and reduces the overall space requirements.
The integration of the fuel pump with the fuel filter can be accomplished in one of two primary ways. Considering the filter housing as a unitary casting, the fuel pump can be positioned within the housing by enlarging the housing to accommodate both the fuel filter and the fuel pump. This approach is disclosed by U.S. Pat. No. 5,958,237, which issued Sep. 28, 1999 to Cort, et al. The other primary way of integration corresponds to the present invention wherein the fuel pump is mounted directly to the outer surface of the fuel filter housing so as to create a unitized, integrated, single assembly.
One of the advantages of the integration approach of the present invention is the afforded versatility for the selected fuel pump. When the fuel pump is directly mounted to the exterior of the fuel filter housing, the size, shape, and style of pump can be changed without affecting the filter or the housing so long as the mounting interface and the fuel inlet/outlet connection remain compatible.
The exterior mounting also enables a quick and efficient exchange or replacement of the fuel pump without having to open the housing. As a result, different pumps with different capacities or flow rates can be used interchangeably with the same fuel filter so long as the mounting interface for the pump remains compatible with the mounting provisions of the housing and so long as the fuel inlet/fuel outlet connection remains compatible. The integration approach of the present invention also enables the use of a smaller casting for the fuel filter housing and thus there is less material and accordingly less expense as compared to the integration approach of U.S. Pat. No. 5,958,237.
In addition to the described integration approach of the present invention involving the fuel pump and the fuel filter, there are other improvements provided. The method of integrating the fuel filter lid with the filter element is one such improvement. According to the present invention, the fuel filter endplate which is integrally bonded to the filter element also functions as the closing lid for the fuel filter housing (casting). In this manner, there is an added simplicity to the design of the present invention. Further, a separate lid does not have to be provided and handled. The endplate/lid design utilizes a knob for easy removal of the "lid" and thus removal of the filter element without the need for any hand tool or special implement. Another improvement of the present invention includes the addition of an air bleed hole in order to reduce the amount of fuel vapor trapped inside of the closed fuel filter housing. Vapor trapped upon closing of the housing or generated during operation is able to bleed into a fuel return line, thereby preventing this vapor from reaching the combustion area of the engine.
The design features included as part of the present invention provide improvements to the design of the fuel filter and the integration of the fuel pump with the fuel filter and its corresponding housing. These design features are novel and unobvious advances in the art.